// /* 
//  * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message 
//  * Digest Algorithm, as defined in RFC 1321. 
//  * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002. 
//  * Code also contributed by Greg Holt 
//  * See http://pajhome.org.uk/site/legal.html for details. 
//  */

// /* 
//  * Add integers, wrapping at 2^32. This uses 16-bit operations internally 
//  * to work around bugs in some JS interpreters. 
//  */
// function safe_add(x, y) {
//     var lsw = (x & 0xFFFF) + (y & 0xFFFF)
//     var msw = (x >> 16) + (y >> 16) + (lsw >> 16)
//     return (msw << 16) | (lsw & 0xFFFF)
//   }

//   /* 
//    * Bitwise rotate a 32-bit number to the left. 
//    */
//   function rol(num, cnt) {
//     return (num << cnt) | (num >>> (32 - cnt))
//   }

//   /* 
//    * These functions implement the four basic operations the algorithm uses. 
//    */
//   function cmn(q, a, b, x, s, t) {
//     return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
//   }
//   function ff(a, b, c, d, x, s, t) {
//     return cmn((b & c) | ((~b) & d), a, b, x, s, t)
//   }
//   function gg(a, b, c, d, x, s, t) {
//     return cmn((b & d) | (c & (~d)), a, b, x, s, t)
//   }
//   function hh(a, b, c, d, x, s, t) {
//     return cmn(b ^ c ^ d, a, b, x, s, t)
//   }
//   function ii(a, b, c, d, x, s, t) {
//     return cmn(c ^ (b | (~d)), a, b, x, s, t)
//   }

//   /* 
//    * Calculate the MD5 of an array of little-endian words, producing an array 
//    * of little-endian words. 
//    */
//   function coreMD5(x) {
//     var a = 1732584193
//     var b = -271733879
//     var c = -1732584194
//     var d = 271733878

//     for (var i = 0; i < x.length; i += 16) {
//       var olda = a
//       var oldb = b
//       var oldc = c
//       var oldd = d

//       a = ff(a, b, c, d, x[i + 0], 7, -680876936)
//       d = ff(d, a, b, c, x[i + 1], 12, -389564586)
//       c = ff(c, d, a, b, x[i + 2], 17, 606105819)
//       b = ff(b, c, d, a, x[i + 3], 22, -1044525330)
//       a = ff(a, b, c, d, x[i + 4], 7, -176418897)
//       d = ff(d, a, b, c, x[i + 5], 12, 1200080426)
//       c = ff(c, d, a, b, x[i + 6], 17, -1473231341)
//       b = ff(b, c, d, a, x[i + 7], 22, -45705983)
//       a = ff(a, b, c, d, x[i + 8], 7, 1770035416)
//       d = ff(d, a, b, c, x[i + 9], 12, -1958414417)
//       c = ff(c, d, a, b, x[i + 10], 17, -42063)
//       b = ff(b, c, d, a, x[i + 11], 22, -1990404162)
//       a = ff(a, b, c, d, x[i + 12], 7, 1804603682)
//       d = ff(d, a, b, c, x[i + 13], 12, -40341101)
//       c = ff(c, d, a, b, x[i + 14], 17, -1502002290)
//       b = ff(b, c, d, a, x[i + 15], 22, 1236535329)

//       a = gg(a, b, c, d, x[i + 1], 5, -165796510)
//       d = gg(d, a, b, c, x[i + 6], 9, -1069501632)
//       c = gg(c, d, a, b, x[i + 11], 14, 643717713)
//       b = gg(b, c, d, a, x[i + 0], 20, -373897302)
//       a = gg(a, b, c, d, x[i + 5], 5, -701558691)
//       d = gg(d, a, b, c, x[i + 10], 9, 38016083)
//       c = gg(c, d, a, b, x[i + 15], 14, -660478335)
//       b = gg(b, c, d, a, x[i + 4], 20, -405537848)
//       a = gg(a, b, c, d, x[i + 9], 5, 568446438)
//       d = gg(d, a, b, c, x[i + 14], 9, -1019803690)
//       c = gg(c, d, a, b, x[i + 3], 14, -187363961)
//       b = gg(b, c, d, a, x[i + 8], 20, 1163531501)
//       a = gg(a, b, c, d, x[i + 13], 5, -1444681467)
//       d = gg(d, a, b, c, x[i + 2], 9, -51403784)
//       c = gg(c, d, a, b, x[i + 7], 14, 1735328473)
//       b = gg(b, c, d, a, x[i + 12], 20, -1926607734)

//       a = hh(a, b, c, d, x[i + 5], 4, -378558)
//       d = hh(d, a, b, c, x[i + 8], 11, -2022574463)
//       c = hh(c, d, a, b, x[i + 11], 16, 1839030562)
//       b = hh(b, c, d, a, x[i + 14], 23, -35309556)
//       a = hh(a, b, c, d, x[i + 1], 4, -1530992060)
//       d = hh(d, a, b, c, x[i + 4], 11, 1272893353)
//       c = hh(c, d, a, b, x[i + 7], 16, -155497632)
//       b = hh(b, c, d, a, x[i + 10], 23, -1094730640)
//       a = hh(a, b, c, d, x[i + 13], 4, 681279174)
//       d = hh(d, a, b, c, x[i + 0], 11, -358537222)
//       c = hh(c, d, a, b, x[i + 3], 16, -722521979)
//       b = hh(b, c, d, a, x[i + 6], 23, 76029189)
//       a = hh(a, b, c, d, x[i + 9], 4, -640364487)
//       d = hh(d, a, b, c, x[i + 12], 11, -421815835)
//       c = hh(c, d, a, b, x[i + 15], 16, 530742520)
//       b = hh(b, c, d, a, x[i + 2], 23, -995338651)

//       a = ii(a, b, c, d, x[i + 0], 6, -198630844)
//       d = ii(d, a, b, c, x[i + 7], 10, 1126891415)
//       c = ii(c, d, a, b, x[i + 14], 15, -1416354905)
//       b = ii(b, c, d, a, x[i + 5], 21, -57434055)
//       a = ii(a, b, c, d, x[i + 12], 6, 1700485571)
//       d = ii(d, a, b, c, x[i + 3], 10, -1894986606)
//       c = ii(c, d, a, b, x[i + 10], 15, -1051523)
//       b = ii(b, c, d, a, x[i + 1], 21, -2054922799)
//       a = ii(a, b, c, d, x[i + 8], 6, 1873313359)
//       d = ii(d, a, b, c, x[i + 15], 10, -30611744)
//       c = ii(c, d, a, b, x[i + 6], 15, -1560198380)
//       b = ii(b, c, d, a, x[i + 13], 21, 1309151649)
//       a = ii(a, b, c, d, x[i + 4], 6, -145523070)
//       d = ii(d, a, b, c, x[i + 11], 10, -1120210379)
//       c = ii(c, d, a, b, x[i + 2], 15, 718787259)
//       b = ii(b, c, d, a, x[i + 9], 21, -343485551)

//       a = safe_add(a, olda)
//       b = safe_add(b, oldb)
//       c = safe_add(c, oldc)
//       d = safe_add(d, oldd)
//     }
//     return [a, b, c, d]
//   }

//   /* 
//    * Convert an array of little-endian words to a hex string. 
//    */
//   function binl2hex(binarray) {
//     var hex_tab = "0123456789abcdef"
//     var str = ""
//     for (var i = 0; i < binarray.length * 4; i++) {
//       str += hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) +
//         hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8)) & 0xF)
//     }
//     return str
//   }

//   /* 
//    * Convert an array of little-endian words to a base64 encoded string. 
//    */
//   function binl2b64(binarray) {
//     var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
//     var str = ""
//     for (var i = 0; i < binarray.length * 32; i += 6) {
//       str += tab.charAt(((binarray[i >> 5] << (i % 32)) & 0x3F) |
//         ((binarray[i >> 5 + 1] >> (32 - i % 32)) & 0x3F))
//     }
//     return str
//   }

//   /* 
//    * Convert an 8-bit character string to a sequence of 16-word blocks, stored 
//    * as an array, and append appropriate padding for MD4/5 calculation. 
//    * If any of the characters are >255, the high byte is silently ignored. 
//    */
//   function str2binl(str) {
//     var nblk = ((str.length + 8) >> 6) + 1 // number of 16-word blocks  
//     var blks = new Array(nblk * 16)
//     for (var i = 0; i < nblk * 16; i++) blks[i] = 0
//     for (var i = 0; i < str.length; i++)
//       blks[i >> 2] |= (str.charCodeAt(i) & 0xFF) << ((i % 4) * 8)
//     blks[i >> 2] |= 0x80 << ((i % 4) * 8)
//     blks[nblk * 16 - 2] = str.length * 8
//     return blks
//   }

//   /* 
//    * Convert a wide-character string to a sequence of 16-word blocks, stored as 
//    * an array, and append appropriate padding for MD4/5 calculation. 
//    */
//   function strw2binl(str) {
//     var nblk = ((str.length + 4) >> 5) + 1 // number of 16-word blocks  
//     var blks = new Array(nblk * 16)
//     for (var i = 0; i < nblk * 16; i++) blks[i] = 0
//     for (var i = 0; i < str.length; i++)
//       blks[i >> 1] |= str.charCodeAt(i) << ((i % 2) * 16)
//     blks[i >> 1] |= 0x80 << ((i % 2) * 16)
//     blks[nblk * 16 - 2] = str.length * 16
//     return blks
//   }

//   /* 
//    * External interface 
//    */
//   function hexMD5(str) { return binl2hex(coreMD5(str2binl(str))) }
//   function hexMD5w(str) { return binl2hex(coreMD5(strw2binl(str))) }
//   function b64MD5(str) { return binl2b64(coreMD5(str2binl(str))) }
//   function b64MD5w(str) { return binl2b64(coreMD5(strw2binl(str))) }
//   /* Backward compatibility */
//   function calcMD5(str) { return binl2hex(coreMD5(str2binl(str))) }
//   module.exports = {
//     hexMD5: hexMD5,
//     hexMD5w: hexMD5w,
//     b64MD5: b64MD5,
//     b64MD5w: b64MD5w
//   }  

// 第二种加密


var rotateLeft = function (lValue, iShiftBits) {
  return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits));
}

var addUnsigned = function (lX, lY) {
  var lX4, lY4, lX8, lY8, lResult;
  lX8 = (lX & 0x80000000);
  lY8 = (lY & 0x80000000);
  lX4 = (lX & 0x40000000);
  lY4 = (lY & 0x40000000);
  lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF);
  if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
  if (lX4 | lY4) {
    if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
    else return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
  } else {
    return (lResult ^ lX8 ^ lY8);
  }
}

var F = function (x, y, z) {
  return (x & y) | ((~x) & z);
}

var G = function (x, y, z) {
  return (x & z) | (y & (~z));
}

var H = function (x, y, z) {
  return (x ^ y ^ z);
}

var I = function (x, y, z) {
  return (y ^ (x | (~z)));
}

var FF = function (a, b, c, d, x, s, ac) {
  a = addUnsigned(a, addUnsigned(addUnsigned(F(b, c, d), x), ac));
  return addUnsigned(rotateLeft(a, s), b);
};

var GG = function (a, b, c, d, x, s, ac) {
  a = addUnsigned(a, addUnsigned(addUnsigned(G(b, c, d), x), ac));
  return addUnsigned(rotateLeft(a, s), b);
};

var HH = function (a, b, c, d, x, s, ac) {
  a = addUnsigned(a, addUnsigned(addUnsigned(H(b, c, d), x), ac));
  return addUnsigned(rotateLeft(a, s), b);
};

var II = function (a, b, c, d, x, s, ac) {
  a = addUnsigned(a, addUnsigned(addUnsigned(I(b, c, d), x), ac));
  return addUnsigned(rotateLeft(a, s), b);
};

var convertToWordArray = function (string) {
  var lWordCount;
  var lMessageLength = string.length;
  var lNumberOfWordsTempOne = lMessageLength + 8;
  var lNumberOfWordsTempTwo = (lNumberOfWordsTempOne - (lNumberOfWordsTempOne % 64)) / 64;
  var lNumberOfWords = (lNumberOfWordsTempTwo + 1) * 16;
  var lWordArray = Array(lNumberOfWords - 1);
  var lBytePosition = 0;
  var lByteCount = 0;
  while (lByteCount < lMessageLength) {
    lWordCount = (lByteCount - (lByteCount % 4)) / 4;
    lBytePosition = (lByteCount % 4) * 8;
    lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition));
    lByteCount++;
  }
  lWordCount = (lByteCount - (lByteCount % 4)) / 4;
  lBytePosition = (lByteCount % 4) * 8;
  lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition);
  lWordArray[lNumberOfWords - 2] = lMessageLength << 3;
  lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29;
  return lWordArray;
};

var wordToHex = function (lValue) {
  var WordToHexValue = "",
    WordToHexValueTemp = "",
    lByte, lCount;
  for (lCount = 0; lCount <= 3; lCount++) {
    lByte = (lValue >>> (lCount * 8)) & 255;
    WordToHexValueTemp = "0" + lByte.toString(16);
    WordToHexValue = WordToHexValue + WordToHexValueTemp.substr(WordToHexValueTemp.length - 2, 2);
  }
  return WordToHexValue;
};

var uTF8Encode = function (string) {
  string = string.replace(/\x0d\x0a/g, "\x0a");
  var output = "";
  for (var n = 0; n < string.length; n++) {
    var c = string.charCodeAt(n);
    if (c < 128) {
      output += String.fromCharCode(c);
    } else if ((c > 127) && (c < 2048)) {
      output += String.fromCharCode((c >> 6) | 192);
      output += String.fromCharCode((c & 63) | 128);
    } else {
      output += String.fromCharCode((c >> 12) | 224);
      output += String.fromCharCode(((c >> 6) & 63) | 128);
      output += String.fromCharCode((c & 63) | 128);
    }
  }
  return output;
};

function md5(string) {
  var x = Array();
  var k, AA, BB, CC, DD, a, b, c, d;
  var S11 = 7,
    S12 = 12,
    S13 = 17,
    S14 = 22;
  var S21 = 5,
    S22 = 9,
    S23 = 14,
    S24 = 20;
  var S31 = 4,
    S32 = 11,
    S33 = 16,
    S34 = 23;
  var S41 = 6,
    S42 = 10,
    S43 = 15,
    S44 = 21;
  string = uTF8Encode(string);
  x = convertToWordArray(string);
  a = 0x67452301;
  b = 0xEFCDAB89;
  c = 0x98BADCFE;
  d = 0x10325476;
  for (k = 0; k < x.length; k += 16) {
    AA = a;
    BB = b;
    CC = c;
    DD = d;
    a = FF(a, b, c, d, x[k + 0], S11, 0xD76AA478);
    d = FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756);
    c = FF(c, d, a, b, x[k + 2], S13, 0x242070DB);
    b = FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE);
    a = FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF);
    d = FF(d, a, b, c, x[k + 5], S12, 0x4787C62A);
    c = FF(c, d, a, b, x[k + 6], S13, 0xA8304613);
    b = FF(b, c, d, a, x[k + 7], S14, 0xFD469501);
    a = FF(a, b, c, d, x[k + 8], S11, 0x698098D8);
    d = FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF);
    c = FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1);
    b = FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE);
    a = FF(a, b, c, d, x[k + 12], S11, 0x6B901122);
    d = FF(d, a, b, c, x[k + 13], S12, 0xFD987193);
    c = FF(c, d, a, b, x[k + 14], S13, 0xA679438E);
    b = FF(b, c, d, a, x[k + 15], S14, 0x49B40821);
    a = GG(a, b, c, d, x[k + 1], S21, 0xF61E2562);
    d = GG(d, a, b, c, x[k + 6], S22, 0xC040B340);
    c = GG(c, d, a, b, x[k + 11], S23, 0x265E5A51);
    b = GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA);
    a = GG(a, b, c, d, x[k + 5], S21, 0xD62F105D);
    d = GG(d, a, b, c, x[k + 10], S22, 0x2441453);
    c = GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681);
    b = GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8);
    a = GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6);
    d = GG(d, a, b, c, x[k + 14], S22, 0xC33707D6);
    c = GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87);
    b = GG(b, c, d, a, x[k + 8], S24, 0x455A14ED);
    a = GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905);
    d = GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8);
    c = GG(c, d, a, b, x[k + 7], S23, 0x676F02D9);
    b = GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A);
    a = HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942);
    d = HH(d, a, b, c, x[k + 8], S32, 0x8771F681);
    c = HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122);
    b = HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C);
    a = HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44);
    d = HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9);
    c = HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60);
    b = HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70);
    a = HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6);
    d = HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA);
    c = HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085);
    b = HH(b, c, d, a, x[k + 6], S34, 0x4881D05);
    a = HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039);
    d = HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5);
    c = HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8);
    b = HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665);
    a = II(a, b, c, d, x[k + 0], S41, 0xF4292244);
    d = II(d, a, b, c, x[k + 7], S42, 0x432AFF97);
    c = II(c, d, a, b, x[k + 14], S43, 0xAB9423A7);
    b = II(b, c, d, a, x[k + 5], S44, 0xFC93A039);
    a = II(a, b, c, d, x[k + 12], S41, 0x655B59C3);
    d = II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92);
    c = II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D);
    b = II(b, c, d, a, x[k + 1], S44, 0x85845DD1);
    a = II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F);
    d = II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0);
    c = II(c, d, a, b, x[k + 6], S43, 0xA3014314);
    b = II(b, c, d, a, x[k + 13], S44, 0x4E0811A1);
    a = II(a, b, c, d, x[k + 4], S41, 0xF7537E82);
    d = II(d, a, b, c, x[k + 11], S42, 0xBD3AF235);
    c = II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB);
    b = II(b, c, d, a, x[k + 9], S44, 0xEB86D391);
    a = addUnsigned(a, AA);
    b = addUnsigned(b, BB);
    c = addUnsigned(c, CC);
    d = addUnsigned(d, DD);
  }
  var tempValue = wordToHex(a) + wordToHex(b) + wordToHex(c) + wordToHex(d);
  return tempValue.toLowerCase();
}
module.exports = {
  md5
}



